Development of Tri-layered Biomimetic Atelocollagen Scaffolds with Interfaces for Osteochondral Tissue Engineering.

The development of biomimetic scaffolds containing cartilage, calcified cartilage, and bone regeneration for precise osteochondral repair remains a challenge. We describe here, a novel tri-layered scaffold-with a top layer containing type II atelocollagen and chondroitin sulphate for cartilage regeneration, an intermediate layer with type II atelocollagen and hydroxyapatite for calcified cartilage formation, and a bottom layer with type I atelocollagen and hydroxyapatite for bone growth-that can be built using liquid-phase co-synthesis. The tri-layered scaffolds that we have designed are mechanically demonstrably superior and have a lower risk of delamination than monolayer scaffolds. This is due to higher cohesion arising from the interfaces between each layer in the tri-layered scaffold. Our in vitro results show that although monolayer scaffolds can stimulate bone marrow stem cells to differentiate and form cartilage, calcified cartilage, and bone separately (detected using quantitative PCR analysis and staining with safranin-O and Alizarin Red S), our tri-layered scaffolds support the regeneration of cartilage, calcified cartilage, and bone simultaneously after 2 and 4 months of implantation (detected using gross and micro-CT images, histological staining, and Avizo, a software that is a powerful 3D reconstruction tool used to detect micro-level defects in metals). Our work presents data on a promising approach in devising strategies for the precise repair of osteochondral defects. This article is protected by copyright. All rights reserved.